Thursday, August 18, 2011

Building Spike Grenades from HALO 3

I've made oodles and gobs of UNSC weapons from HALO3. So when Dan Wang, director of the upcoming HALO fan film Helljumper, put it to me to make some the Brute spike grenades I thought, "why not?" For those of you who don't play video games, here's what this particular device looks like in the game:

According to the references I've found, this thing is supposed to be 36 inches long. To me, that seems a bit on the ridiculous side. There's an image from halo.bungie.org that gives you a bit of an idea of approximately how ridiculous it is.

With that in mind, I cobbled together a mockup to help me figure out what would look and feel big without making me look like an infant playing with grandpa's collection of antique German potato masher grenades. Here's what I came up with.

Since the mock-up looked slightly less than screen accurate, I scribbled down some measurements, chopped up an old fencepost, and started turning down a prototype on the lathe:

After about an hour, it looked like so:

I was working with a really crappy piece of wood with lots of knots and splits, so this is what the good side looked like:

The next step was to seal up the surface and coat it so I could get a smoother surface. I used Bondo:

Here I am smoothing out the bondo with some 100-grit sandpaper:

This is about the time I noticed that I still had a big chunk of rotten fencepost left over and I was mostly just using one hand to work on the spike grenade prototype. This left my other hand to start work on the main body of a frag grenade as well:

With a bit more work and some hammered-finish paint, here's what I had:

I textured the top too:

Same process for butt end of grip:

The spikes were cut from scraps of plastic sheet I had laying around:

Once they were cut out, I went ahead and beveled the edges to make them look sharp. In the process I covered myself and everything around me with white plastic dust:

Each spike grenade has 20 different spikes. They are four different shapes (one is used twice), so I only would've made one of each if I had time to kill. Unfortunately, I was in a rush. So instead of molding four sets of five blades for each grenade, I decided on one big box mold to make the blades 20 at a time. Here's all of the blades lined up and prepped for molding:

After I'd built molds and poured the first casting in foam, here's what it looked like:

The head and butt ends were cast in a fairy dense flexfoam. This way, the grenade can take a bit of abuse without being destroyed. I planned to make the blades out of foam too, but they just looked too floppy that way. The next best thing was to make them out of rigid resin and hope the foam they were attached to would flex enough to bounce.

I used 1" PVC conduit for the shafts. To bond everything together, I place the conduit into the mold for the head as the foam is curing, then flip it and put the other end into the mold for the butt end. When the foam for the second end cured, all that was left was to glue on the spikes, paint and weather the whole thing, then wrap the shaft with some dark brown upholstery vinyl.

Here's one of them all painted up:

Here's the first pair all together:

Success!

The frag grenades came out pretty good too:

Sooner or later I'll find someone who can juggle these so I can shoot some video.